Robert mitchell and charles lawson



(No Model.)

' R. MITOHELLI8ZZ C. LAWSON.

GAS METER.

Patented Mar. 3,1891.

ZZ W/ Miran STATES PATENT Fries.

ROBERT MITCHELL AND CHARLES LAIVSON, OF MONTREAL, CANADA.

GAS-METER.

SPECIFICATION forming part of Letters Patent No. 447,693, dated March 3, 1891.

Application filed March 14, 1890. Serial No. 343,906. (No model.) Patented in CanadaApril 2, 1890, No. 34,038.

To all whom it may concern:

Be it known that we, ROBERT MITCHELL, manufacturer, and CHARLES LAWSON, metermaker, both of the city of Montreal, in the district of Montreal and Province of Quebec, Canada, have invented certain new and useful Improvements in Gas-Meters, (for which we have obtained Letters Patent of Canada, No. 34,038, dated April 2, 1890;) and we do hereby declare that the following is a full, clear, and exact description of the same.

This invention comprises certain improvements in the construction of gas-meters, and has for its object to produce a meter having its working parts more durable in operation and more easily cleaned, replaced, and put in order when reparation is needed.

In order to do away with the defects of the present method of securing the bellows expansible sides to the front and back plates in which theleather is scorched and hardened by the heat from the soldering onto the plates of the retaining-beads, we propose to spin or turn up on the rim of the plates a flange composed of a double head with a groove between them,in which is laid the edge of the leather. This is held in place by wire or metal bands passed round over it, one end being secured by solder to the turned-up edge of each plate, and to allow of access to the inside of the diaphragm-chambers for the purpose of cleaning and putting the parts together easily we cut out originallyfrom the back plate a large concentric opening, and cover this with a plate secured thereon by any suitable means. This is taken off when the diaphragm-chamber sections are taken out of the meter, thereby allowing free access to the interior of the chambers and enabling an unskilled operator to perform all that is necessary, even to renewin g the leathers,whieh, being put in on a block in the usual way, are secured to both plates simply by laying their edges in the grooves and winding the wire or band round them. We further propose to make the valves controlling the influx of the gas into the diaphragm-chamber with the grating or valveseat separate from the valve-plate, so as to allow of their being easily removed for the purpose of being cleaned, &c.,-allowing them also to be accurately trued up to compensate for wear. This section (valves and grating) may with the first section of the pipes be a casting in one piece of incorrodible metal.

For full comprehension of the invention reference must be had to the annexed drawings, forming part of this specification, in which- Figure l is a back view of a diaphragm; Fig. 2, a vertical section of same; Fig. 3, a top view of valve-plate; Fig. 4:, a bottom view of same, and Fig. 5 a detail vertical section taken longitudinally of one of the valvegratings:

Similar letters of reference indicate like parts.

It will be observed that in the drawings the well-known parts of a gas-meter in which no change is madeare not indicated.

A is the frame of the meter, and B and C, respectively, the inlet and outlet pipes, b and 0 being, respectively, the openings between those and the inlets into and exhaust from the diaphragm-chamber.

E is the expansible diaphragm-chamber, F being the front plate, G the back one, and II the expansible leather.

On the inside of each of the plates we spin or turn up a flange composed of a double bead ff g g, with grooves f g between them. In these grooves f g are laid the edges of the leather,which are secured in place by lengths of wire K K, having one end soldered to the turned-up edges of the plates F G (usually before the leather is laid on) and wound round over the leather, holding it firmly in place in the grooves f g and making a perfectly-tight joint, the other ends of the wire being secured in any usual way. By this means all necessity for the the application of heat to secure the leather and plates together is done away with and all chance of burning or hardening the leather, so as to cause it to crack in use, is obviated.

Instead of the wires K K alength or lengths of thin strips maybe used and secured in any desired way.

In the back plate G is cut, as shownin dotted lines in Fig. l, a concentric aperture, and this is closed, as shown in Fig. 2, by a plate G which maybe soldered in .place or secured to G by projections and pins, or in any other suitable way, should it be thought best to avoid the use of heat-such, for instance, as

three or more bayonet-checks, with a wedgeshaped indentation to tighten it up and putty joints. This plate G when the diaphragm is taken out of the frame, is easily removed, giving access to the interior of the expausible diaphragm-ehamber without the necessity of taking apart the plates and leather, thus enabling an unskilled workman to do all that is required for cleaning the same, and in the original construction of the diaphragm the opening is of special value in allowing the parts to be more easily secured together.

I11 Figs. 3, at, and 5 is shown, as far as is required for illustrating the present invention, the arrangement of the parts for el'tectin g and regulating the influx and ettiux of the gas.

Q is the valve-plate, to which are secured by means of screws or bolts (1 and nuts q, as shown in Fig. 5, separate plates Q carrying the gratings and valves governing the supply of gas to the expansible diaphragmchamber, which are of the usual type.

R is the inlet taken from the inlet-pipe 1) to the top communicating chamber b. T is the pipe from this chamber to the diaphragmehainber, the upper part of which may be made in one with the plate Q, and the lower part or that connected with the diaphragm-chamber be a slip-joint, the flange of the back plate of the diaphragm at the point of junction of this pipe being flattened out to receive it.

U is the exhaust taken to the outlet-pipe C.

\Vhat we claim is as follows:

In a gasmeter, the diaphragm composed of the front plate having an inwardly-proj ecting flange and expansible leather sides and back plate having an aperture therein and plate normally covering same and an inwardlyprojecting flange, as and for the purposes set forth.

llliontreal, March 5, 1890.

ROBERT MITCHELL. ("I IAS. LJUVSON.

In presence of WM. P. lllcl nivr, OWENN GRAVE. 

